Monday, October 01, 2012

During the last few months, talk about building a subway in Scarborough has been cropping up again. Personally, I find this a little worrisome. Although my usual philosophy towards transit is that is that building anything is better than building nothing, building a subway is Scarborough just seems like a big waste of money that will sap money away from more important projects. Subways exist because they provide capacity and speed for transit users. There is no evidence that Scarborough is in need of either. If there were capacity problems, the TTC would be running high capacity buses in dedicated bus lanes, but they're only starting to consider deploying high capacity buses now. If speed were a problem, the TTC would offer a highway 401 bus or have special buses to redirect people to GO train stations, but they aren't. The reality is that suburbs are designed for cars and building a mass transit system there for moving hundreds of thousands of people would be a waste of money. In order to achieve increased capacity and speed in a transit system, you need space. In high density areas, there's no space, so you need to build subways. In the suburbs, there's plenty of space, so there's no need to build subways to achieve capacity and speed goals. For the price of a subway, you could probably just buy out whole suburban neighbourhoods, plow them under, and build a fast surface bus or train instead.

But to make sure I wasn't judging anything unfairly though, I decided that maybe it would be good idea to run some simulations to see what the effect of different subways plans would be. Following the same experimentalmethodologyfrom my previous simulations, I ran some simulations of the effect of different plans on transit times to downtown. I believe that all of these plans would end up costing around $1bn-$2bn. Following the METROLINX guides, surface LRTs are modeled as having an average speed of 22km/h while grade-separated LRTs and subways are modeled as having an average speed of 32km/h. The future Eglinton LRT is included in the simulations even though it does not offer any benefits to people in Scarborough going downtown (though it would useful for people going to midtown).

Current System

As a baseline, here is a map of transit times of the current transit system in Scarborough. This system is actually unsustainable because the Scarborough RT line from Kennedy station to Scarborough Town Centre is obsolete, over-capacity, and needs replacement.

From the map, it can be seen that most transit users in Scarborough need about an hour to reach downtown. Most transit users don't live near a transit line, so they need to take a bus to the Scarborough RT line or to the Yonge line in order to reach downtown (people north of the 401 who don't live on Sheppard generally don't take the Sheppard subway because it only comes once every 7 minutes, so it's faster and more convenient for people to take an express bus direct to the Yonge line). Scarborough is laid out as a grid of major roads. Inside each grid square is a tangle of residential roads that are generally impassable by buses. As such, a transit user must walk to the nearest major grid road and take a bus from there. I suspect that this is part of the reason for the short distance between bus stops (as compared to suburban bus systems in other cities). Although this results in slower buses, transit users already have to walk some distance to reach a major road where buses run, and it would be unfair if they have to walk another half kilometre along the road to reach a bus stop. Buses in Scarborough generally run along these major roads, forming a gridpattern. One exception to this pattern is that many buses are rerouted to Scarborough Town Centre, which is intended as a transit hub for Scarborough.

Sheppard LRT with SRT Revamp and Extension

The default transit extension that will be built by the Ontario government if there is no political interference is an LRT along Sheppard and an extension of the SRT to Sheppard and Markham. The Sheppard LRT is modeled as coming with a six minute frequency, similar to the frequency suggested by METROLINX for the Eglinton LRT. The frequency of the SRT was not adjusted (I think it has a 3-4 minute frequency during rush hour) even though it will likely come less frequently after the revamp because newer high capacity trains will be used on the line after the change.

Transit times to downtown with a Sheppard LRT and SRT extension.
Data, imagery and map information provided by MapQuest,Open Street Map and contributors, CC-BY-SA.

The Sheppard LRT does not provide any benefit over the existing system. Current Rocket express buses already reach an average speed of around 20km/h, which is similar to the speeds expected to be achieved by the LRT. The Rocket express buses also come more frequently than the LRT, so the LRT won't provide any benefit over the existing bus system in terms of transit times. The LRT will likely be cheaper to run than the bus system though. The SRT extension does seem to save transit users living on Markham south of the 401 about 10 minutes. People who live along Sheppard in Malvern will also see savings of about 5 minutes in transit times. These time savings might disappear though if the revamped SRT is run at a lesser frequency than it currently does since all the time savings of having a faster mode of transport will be lost by having to wait longer for the train to arrive.

Sheppard Subway Extension to Victoria Park

Historically, the long-term plan for a subway in Scarborough is an extension of the Sheppard subway to the Scarborough Town Centre. This would be prohibitively expensive, so current suggestions are that an extension of the Sheppard subway to Victoria Park could be used as an intermediate step to demonstrate the benefits of a full subway.

Transit times to downtown with a Sheppard subway extension to Victoria Park.
Data, imagery and map information provided by MapQuest,Open Street Map and contributors, CC-BY-SA.

A subway extension to Victoria Park provides a ten minute in transit times for people who live at Victoria Park. People who live on Victoria Park near Sheppard will see a 5-8 minute improvement since they don't have to change buses at Sheppard in order to get to the Sheppard subway at Don Mills. People living on Sheppard west of Agincourt will see a modest improvement in transit times since they can transfer from a bus to a subway at Victoria Park instead of having to cross the 404.

OneCity Subway

Recently, there has been a suggestion that the SRT should be scrapped and the Bloor subway should be extended to Scarborough Town Centre and then up to Sheppard. This will supposedly result in faster travel through Scarborough because no transfer from the SRT to the subway will be needed at Kennedy subway station.

Transit times to downtown with the OneCity extension of the Bloor subway to Sheppard.
Data, imagery and map information provided by MapQuest,Open Street Map and contributors, CC-BY-SA.

Eliminating the SRT results in a sharp reduction in service in the area around the SRT. There is also a surprising increase in transit times for people living in Agincourt since they no longer have a short bus ride to the SRT. Instead most of the transit benefits of having a nearby transit line are pushed east to the Scarborough hospital and Malvern West.

"Subway" to Pacific Mall

Out of curiosity, I decided to model the effect of scrapping the SRT and building an LRT along the train corridor from Kennedy to Pacific Mall in the north. One problem with building rapid transit lines in Scarborough is that the main transit hub for the area, Scarborough Town Centre, is in the middleof nowhere. It is not near the major transit corridors of Scarborough, so many buses actually have to be redirected from their natural routes in order to reach there. The only major transportation corridor that the Scarborough Town Centre is near is Highway 401. As can be seen from the 2006 strategic plan for the SRT, 75% of SRT users ride a bus to reach it with users mainly coming from Malvern, Malvern West, and the Milliken area. So instead of designing a squiggly line of a system, I decided to see the effect of building the longest, cheapest, grade-separated "subway" possible that would intersect as many existing bus lines as possible--i.e. an LRT along the current train corridor from Kennedy to Pacific Mall. Such a line has more potential for provincial and federal government support since it serves multiple regions (Markham and Scarborough) at a modest cost, can be easily extended later on to the Highway 7 BRT, and much of the electrical infrastructure will be needed in the future anyway for the GO train network. This LRT was modeled as having a frequency of six minutes. Unfortunately, it's not really possible to model the effect of such a transit line accurately since many of the current bus lines are designed to send people to Scarborough Town Centre; whereas, in this system, buses would mainly run east-west so as to dump people off at the rapid transit line running through the middle of Scarborough.

Transit times to downtown with an LRT along the train corridor to Pacific Mall.
Data, imagery and map information provided by MapQuest,Open Street Map and contributors, CC-BY-SA.

Unfortunately, the simulations show only modest benefits from such a system. Near Sheppard, the train corridor is a little too far from Kennedy and Midland to make walking there worthwhile as compared to taking a bus down to the SRT. At a frequency of every six minutes, transfers to the line take too long, and transit users will often find it easier to simply take a bus directly to the Yonge subway. Arguably, the same thing will happen in a revamped SRT if it has a six minute frequency as well though. I think this scenario is too difficult to simulate using my current approach, so it's impossible to compare it with other approaches.

Conclusion

The pressure to build a subway in Scarborough seems to be based primarily on politics than on a genuine need. They feel that they deserve a transit showpiece comparable to what's available in northern and south-western Toronto. This is not a bad thing, but it means that potential transit plans should be evaluated primarily in terms of minimizing construction and operating costs. The cheapest transit line that satisfies the political needs without damaging the existing transit system too much.

For this reason, I actually think the Sheppard LRT and SRT extension project is probably best. Surprisingly, this project will actually result in worse transit times for people living in Scarborough because the increased capacity of the new lines will mean that transit will likely be less frequent than the current system. The project will likely have lower operating costs than the current system, which is the main benefit of building it. The grid spacing of Scarborough also seems to favour east-west transit lines over north-south transit lines because it's often a shorter walk to get to a north-south bus line (which can then take you to an east-west rapid transit line) than to get to an east-west bus line. To save even more money on construction costs, it might even make sense to abandon the Sheppard LRT and only build the SRT extension since the Sheppard LRT doesn't actually do anything interesting from a transit perspective.

Of the two plans that actually involve building real subways--the OneCity plan and the Victora Park extension--I actually prefer the Victoria Park extension. The OneCity plan is more expensive and the expense mostly goes towards shifting an existing transit corridor 2km to the east for no particular benefit. Overall though, I think both plans are bad because they are expensive, unnecessary, and will likely increase operating costs for the TTC. In any case, neither of these plans are feasible because neither the city nor the province have the means to pay for it. The province has run out of money, and my understanding is that they can only find money for new construction through the use of accounting tricks. They are mainly interested in building self-contained new transit lines that can be leased to private industry or mortgaged, thereby allowing the province to hide the cost of the construction by spreading it over many decades instead paying for construction upfront or something complicated like that. Subway extensions aren't self-contained, so they can't be owned and operated independently by private companies, so they don't qualify for accounting trickery, so the province can't fund them.

I'm still partial to my idea of building a "subway" to Pacific Mall. It's a big transit showpiece that can be built at a modest cost, the surrounding area are likely good candidates for densification, and I believe it would be eligible for provincial funding. Unfortunately, it's hard to simulate the effect of such a massive change to transit, so its effects on transit usage is unclear. It might be a little bit too close to the Yonge subway line, so people might still prefer taking a bus to Yonge and riding the subway downtown as opposed to taking a bus to the train corridor, taking a train to Kennedy, taking a train to Bloor, and then taking the Yonge subway line down into downtown. Also, the abandoning of rapid transit to Scarborough Town Centre is likely too politically controversial for politicians.